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00:01
we do the thorax and axilla as well. The shoulder
joint, a lot of theory. I haven't coverit but you need to just go through the slides
when you have a minute. You can get questionson the rotator cuff, shoulder joint. You need
to understand the glenoid labrum. From thesuperior part, you have the long head of biceps.
From the inferior side, you have the longhead of triceps. So, that is the theory. The
four muscles of the rotator cuff, you needto know. Painful arc syndrome. Painful arc
syndrome is when your supraspinatus tendongets caught under the acromion process.
So supraspinatus initiates the first 15degrees of abduction. Then the deltoid takes
over. Until here is deltoid, and how doesthis movement happen? Which muscle is working?
Supraspinatus deltoid --Trapezium? Yes, very good, and a bit more?
You’re right.
01:23
You’re on the right track. Trapezium, it’s
by the rotation of the scapula.
01:27
Lattisimus? That doesn’t work.
Trapezium is mainly.
01:32
Beyond this, this gives the scapula rotation
rotating on the thorax and this trapeziumis pulling it up. It’s also aided by the
rhomboids. This is your action of the shoulder.
01:43
But if we have a supraspinatus tendinitis
or painful arc syndrome, when it comes to60 degrees, the supraspinatus tendon gets
caught under the acromion process.
01:55
It’s painful, painful, painful all the way up to
120. Now, when you push it more, the tendonmoves off the acromion process and it becomes
pain free. So that is your painful arc syndrome,60 to 120 degrees. Brachial plexus, you can get
this in any book.
02:21
So that’s why I didn’t go through this,
but when you’re revising, you’ll be ableto get all this information for you to understand axillary artery,
what is on the lateral side, what is on the medial sidebranches of the lateral cord, posterior cord, branchesof the medial cord. Just take a minute for
you to orient yourself. You have a lateralcord of the brachial plexus there, axillary
artery, medial cord of the brachial plexus,and then you have the ulnar nerve here,
brachial artery.
03:09
One anatomical relation they’ll ask you in
the exam is, if you go back to the cubitalfossa, the most medial structure is the median
nerve. Next to that is the brachial artery,but if you go up the arm, if you go up here,
it's other way around. So the brachial arteryis medial, median nerve is lateral. As it
comes to the distal one-third of the arm,they cross over so that the median nerve comes
most medial. So that is another anatomic relation.
03:45
Okay. Dermatomes, I’m sure you know this,
but I think I have a picture on that. Okay.
03:56
So, you know that is C5, C6. C6 is your thumb and half
of the index finger. C7 is middle finger.
04:06
C8 is mainly ring and little. T1, T2. So, C5
to T2 in the limb. If you look here, it willbe T3, T4, T5, T6, T7, T8, T9, umbilicus is
T10. T11, T12, L1. C3 and C4, where do theC3 and C4 come from?
Cervical plexus.
04:40
Very good, yes. This is what we’ll be discussing
after the break. When we discuss the headand neck, we’ll cover the C3, C4. So as
I said, the brachial plexus is starting fromC5. So that’s why the entire arm is C5 to
T1, the inside part is T2. Okay. Cubital fossa,that’s a schematic head of presentation. Laterally,
you have the brachioradialis. Medially, youhave the pronator teres. So, this is the left and
the right cubital fossa. Brachioradialis.
05:20
Pronator teres. Median nerve. Brachial artery.
Cephalic vein. That’s the tendon of biceps.
05:28
So if you look at, that’s your left arm,
medial to lateral, pronator teres, median nerve,brachial artery, biceps, brachioradialis.
Okay. There is nothing new. This is just atheory of what we've discussed, their boundaries,
contents. Carpal tunnel, we’ve been throughit in detail, but this is cross-section. This
is all for further understanding and revisingif you have the time. But as I said, if you
just revise what we have covered this morning,that should be sufficient for your exam.

About the Lecture

The lecture Shoulder Joint by Stuart Enoch, PhD is from the course Musculoskeletal - Upper Limb.

Included Quiz Questions

Which of the following structures does not cross the sternocleidomastoid muscle?

The accessory nerve

The external jugular vein

The great auricular nerve

The transverse cervical nerve

A 47-year-old male was involved in an accident and fractured his humerus. Upon inspection of his arm, he complained of numbness and tingling as well as inability to extend his hand. Which of the following cords of the brachial plexus is associated with the most likely damaged nerve?

Posterior cord

Anterior cord

Superior cord

Inferior cord

Middle cord

A tennis player presents with pain and weakness in his left upper extremity for the past 3 months. He complains of numbness and tingling that developed slowly. Physical exam shows pallor and coolness to the hypertrophied muscles of the upper extremity. Further testing shows damage to the anterior and middle scalene muscles, occluding a large vessel. Which artery is most likely involved?

Subclavian artery

Brachial artery

Brachiocephalic artery

Supraspinatus artery

Which nerve of the brachial plexus Innervates the pectoralis major and pectoralis minor muscles?

Medial pectoral nerve

Posterior pectoral nerve

Anterior pectoral nerve

Median pectoral nerve

Which of the following nerves, if compressed, could lead to crutch palsy?

Axillary nerve

Clavicular nerve

Radial nerve

Median nerve

A 60-year-old female presents to the office with the complaint of left shoulder pain. History reveals that the pain worsened over the last month and is worse with reaching overhead. There is pain with abduction of the right shoulder and internal rotation. X-rays of the shoulder are within normal limits. What is the most likely diagnosis?

Rotator cuff tear

Bicipital tendonitis

Radial nerve tear

Arthritis

A 52-year-old male was bit by a stray dog. X-rays performed were within normal limits. The patient later complained of pain, numbness and tingling at the first three digits of his hand. Which nerve is most likely to be affected by the injury?

Median nerve

Radial nerve

Ulnar nerve

Medial nerve

Which of the following statements about the brachial plexus is true?

The lateral cord continues as the musculocutaneous nerve

The medial cord continues as the musculocutaneous nerve

The lateral cord continues as the axillary nerve

The nerve to subclavius is a branch of the C2 nerve root

A 70-year-old farmer was digging his crops when he suddenly felt weak and heard a “snap” in his upper extremity. He is unable to maintain grip strength and a buldge could be palpated in his mid upper arm. Which is the most likely reason for this finding?

Biceps tendon rupture

Brachioradiallis rupture

Triceps rupture

Humerus fracture

Motorcyclists most commonly present with a hand injury leading to flexion of the 4th and 5th digits due to ulnar abnormalities. Which nerve roots most likely affected in this condition known as “claw hand”?

C8 -T1

T1-T8

C5-C6

C4-C8

Which nerve is most likely to be injured in a patient who cannot abduct his fingers after a laceration from a cooking knife?

Ulnar nerve

Musculocutaneous nerve

Radial nerve

Median nerve

A 21-year-old medical student was injured in the medial aspect of his upper limb, resulting in an inability to adduct his arm. Which muscles are most likely to be injured?

Teres major, pectorlis major, latismus dorsi

Teres minor, pectoralis major, latismus dorsi

Teres major, pectoralis minor, latismus dorsi

Teres minor, pectoralis major, teres major

Following a car accident a patient suffers from cervical spondolysis at C2-C3. Which nerve root is most likely to be affected?

C3

C2

C4

C1

Which of the following muscles if injured could result in difficulty of internal rotation?

Subscapularis muscle

Infraspinatus muscle

Supraspinatus muscle

Teres major

Deltoid

A 46-year-old female housekeeper presented to clinic with weakness and pain in her shoulder. Neer's sign and Hawkins-Kennedy tests were positive. The doctor suggested steroid injections to alleviate symptoms temporarily. X-rays show joint calcification. Which of the following is most likely responsible for such symptoms?

Shoulder impingement

Fractured humerus

Painful arm syndrome

Subscapularis tear

What is the most likely location for the supraspinatus to be caught, resulting in painful arc syndrome?

Acromion process

Clavicle

Coracoid process

Humerus

A 4-year-old child accidentally hammers his own hand and now complains of numbness and tingling in his middle finger. Which nerve root is most likely affected?

C7

T1

C5

C6

C8

A 21-year-old female computer analyst comes into the office complaining of paresthesias, pain and weakness for the past 3 years. It is worse with wrist flexion and extension. The patient has a positive Tinel’s sign. Which nerve is most likely affected based on above findings?

Median nerve

Medial nerve

Ulnar nerve

Radial nerve

Which of the following, when released, relieves the symptoms associated with carpal tunnel syndrome?

Transverse carpal ligament

Vertical carpal ligament

Ulnar nerve

Radial nerve

Which of the following comprises the cubital fossa in order of most medial to most lateral?

Median nerve, brachial artery, biceps brachii tendon, radial nerve

Brachial artery, biceps brachii tendon, radial nerve, median nerve

Brachial artery, median nerve, biceps brachii tendon, radial nerve

Brachial artery, radial nerve, median nerve

Which of the following cords of the brachial plexus contains the following nerves: Musculocutaneous nerve, lateral pectoral nerve, and the lateral root of the median nerve?

Lateral cord

Posterior

Medial

Anterior

What is the order in which the anterior, middle and posterior scalenes is attached?

1st rib, 1st rib, 2nd rib

2nd rib, 1st rib, 1st rib

1st rib, 2nd rib, 3rd rib

2nd rib, 2nd rib, 3rd rib

Which nerve innervating the biceps brachii gives the arm the ability to supinate?

Musculocutaneous nerve

Medial nerve

Ulnar nerve

Radial nerve

Newborns born with hyperabduction and shoulder dystocia are more prone to develop upper brachial plexus injuries. Which nerve roots and nerves would be affected in such complications?

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